It is proposed to operate a Biotechnology Research Center using high-energy x-rays produced by the National Synchrotron Light Source (NSLS) for trace element analysis in a number of biomedical fields. The uniquely high x-ray intensity from the NSLS will be used as the basis of an X-Ray Microprobe Facility which will be able to provide a highly polarized photon flux of about 10 to the 15 photons/square centimeters/sec in a spot of size 2 mm x 2mm. With use of high resolution electron and photon spectrometers multielement detection for essentially all elements in the periodic table will be possible with sensitivities close to one part per billion by weight in times of 5 minutes or less for each sample. A two-dimensional demagnification system will be used to provide focussed spots of 20 Mum or less with similar detection sensitivities. The properties of this system will be investigated to determine the ultimate sensitivities and spatial resolutions that can be obtained. Round-robin studies will be carried out to compare this technique with other analytical methods and to demonstrate its unique features. Studies on selected biomedical topics will be carried out on a collaborative basis.